package com.eveinfo.sql;

import java.io.ByteArrayInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.locks.ReentrantLock;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;

import com.eveinfo.R;

public class PictureBaseHelper extends SQLiteOpenHelper {

	// The Android's default system path of your application database.
	private static String DB_PATH = "/sdcard/eveinfo/";
	private static String DB_NAME = "pictures.db";
	private SQLiteDatabase myDataBase;
	private final Context context;
	private Map<String, BitmapDrawable> cache;

	private ReentrantLock lock = new ReentrantLock();

	/**
	 * Constructor Takes and keeps a reference of the passed context in order to
	 * access to the application assets and resources.
	 * 
	 * @param context
	 */
	public PictureBaseHelper(Context context) {
		super(context, DB_NAME, null, 1);
		this.context = context;
		this.cache = Collections.synchronizedMap(new HashMap<String, BitmapDrawable>());
	}

	/**
	 * Creates a empty database on the system and rewrites it with your own
	 * database.
	 * */
	public void createDataBase() throws IOException {

		boolean dbExist = checkDataBase();

		if (dbExist) {
			// do nothing - database already exist
		} else {

			// By calling this method and empty database will be created into
			// the default system path
			// of your application so we are gonna be able to overwrite that
			// database with our database.
			this.getReadableDatabase();

			try {

				copyDataBase();

			} catch (IOException e) {

				throw new Error("Error copying database");

			}
		}

	}

	/**
	 * Check if the database already exist to avoid re-copying the file each
	 * time you open the application.
	 * 
	 * @return true if it exists, false if it doesn't
	 */
	private boolean checkDataBase() {

		SQLiteDatabase checkDB = null;

		try {
			String myPath = DB_PATH + DB_NAME;
			checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);

		} catch (SQLiteException e) {

			// database does't exist yet.

		}

		if (checkDB != null) {

			checkDB.close();

		}

		return checkDB != null ? true : false;
	}

	/**
	 * Copies your database from your local assets-folder to the just created
	 * empty database in the system folder, from where it can be accessed and
	 * handled. This is done by transfering bytestream.
	 * */
	private void copyDataBase() throws IOException {

		// Open your local db as the input stream
		InputStream myInput = context.getAssets().open(DB_NAME);

		// Path to the just created empty db
		String outFileName = DB_PATH + DB_NAME;

		// Open the empty db as the output stream
		OutputStream myOutput = new FileOutputStream(outFileName);

		// transfer bytes from the inputfile to the outputfile
		byte[] buffer = new byte[1024];
		int length;
		while ((length = myInput.read(buffer)) > 0) {
			myOutput.write(buffer, 0, length);
		}

		// Close the streams
		myOutput.flush();
		myOutput.close();
		myInput.close();

	}

	public void openDataBase() throws SQLException {
		String myPath = DB_PATH + DB_NAME;
		myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);

	}

	@Override
	public void close() {
		if (myDataBase != null)
			myDataBase.close();
	}

	@Override
	public void onCreate(SQLiteDatabase db) {

	}

	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

	}

	public BitmapDrawable getPicture(String name) {
		BitmapDrawable bitmapDrawable = cache.get(name);
		if (bitmapDrawable != null) {
			return bitmapDrawable;
		}
		byte[] result = null;
		BitmapDrawable bitmap = null;
		lock.lock();
		try {
			openDataBase();
			if (myDataBase != null) {
				Cursor query = myDataBase.query("invPictures", new String[] { "picture" }, "name = '" + name + "'",
						null, null, null, null);
				if (query != null) {
					int column = query.getColumnIndex("picture");
					while (query.moveToNext()) {
						result = query.getBlob(column);
						InputStream is = new ByteArrayInputStream(result);
						bitmap = new BitmapDrawable(is);
						break;
					}
					query.close();
				}
			}
			if (bitmap == null) {
				int length = name.length();
				if (name.substring(length - 2, length).equals("32")) {
					bitmap = new BitmapDrawable(BitmapFactory
							.decodeResource(context.getResources(), R.drawable.null_32));
				} else {
					bitmap = new BitmapDrawable(BitmapFactory
							.decodeResource(context.getResources(), R.drawable.null_64));
				}
			}
			cache.put(name, bitmap);
			myDataBase.close();
			return bitmap;
		} finally {
			lock.unlock();
		}
	}

	public void insertPicture(String name, byte[] data) {
		ContentValues initialValues = new ContentValues();
		initialValues.put("name", name);
		initialValues.put("picture", data);
		long rowId = myDataBase.insert("invPictures", null, initialValues);
		System.out.println("row: " + rowId);
	}

	public void deleteCache() {
		cache = null;
		cache = new HashMap<String, BitmapDrawable>();
	}
}
